Raised pavement markers provide better nighttime and wet delineation of traffic lanes than do painted lines and tapes. In some raised pavement markers, a strip of retroreflective material is adhered to a flap which extends upwardly from a base to face oncoming vehicular traffic. Such raised retroreflective pavement markers are disclosed in Jonnes, U.S. Pat. Nos. 3,785,719 (particularly in FIGS. 6 and 7); May, 4,534,673; and Krech et al., 4,521,129.
An applicator for mechanically applying raised retroreflective pavement markers is disclosed in Blomberg, U.S. Pat. No. 3,864,052. In that applicator, the raised pavement markers are arranged in a stack from which a picker carries the bottom marker by its flap into wedging contact between a pavement-engaging wheel and the pavement. Although the Blomberg applicator was in use for a period of time, it is believed that at the present time, all pavement markers are applied by hand, thus making their use expensive and time-consuming.
Most pavement markers are bonded to the pavement by a 2-part thermosetting resin composition which is deposited onto a freshly cleaned spot on the pavement, after which a pavement marker is positioned on the deposit. Since the cleaning and depositing steps are manual, there may be little advantage to using a machine for mechanically positioning the marker unless the first two steps are also mechanical.
For easy removability, as is desirable in temporary bypasses, some pavement markers bear a layer of pressure-sensitive adhesive for bonding the markers either directly to the pavement or to a pavement-striping tape, as do the markers of the above-cited Jonnes patent. Mechanical application of such markers would save both labor and time. When pavement markers are to be applied to a pavement-striping tape which is being applied mechanically, it would be desirable to apply the markers at the same speed, but this would be difficult and inconvenient if the markers must be applied manually. Machines for mechanically applying pavement-striping tape are disclosed in Stenemann, U.S. Pat. Nos. 4,030,958 and 4,242,173.